ЛР10 Программирование (1.7 В21) - IV

LabWork10
📑 IT Online Mini Campus. Task 1.7

IV. Программа SageMath (Python)

E=10^(-4); A,B=E,2-E;

def find_root_div2(f,a,b,e,var):

    pretty_print(html(latex(f)))

    if sign(f(a))==sign(f(b)):

        s='It is not possible to use '

        s+='this decision method for the segment'

        print(s)

    else:

        print('Iteration steps'); t=[['f(a)','f((a+b)/2)','f(b)']]

        while b-a>=e:            

            ab=a+(b-a)/2; t+=[[f(a).n(),f(ab).n(),f(b).n()]]

            if sign(f(a))!=sign(f(ab)):

                if f(ab)==0: break 

                b=ab

            else: a=ab

        show(table(t))

        print('var %d f(x)=0 =>\nprogram answer: x≈%.10f'%(var,ab))

        print('SageMath answer: x≈%.10f'%find_root(f21(x),0,2))

f21(x)=log(20/sqrt(.009))-1.5*(exp(x/3)+exp(-x/3))-x

find_root_div2(f21,A,B,E,21)